Submission #1797604

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Source Code Expand

#include <cstdio>
const int mo=1000000007;
int x[100005];
struct Matrix{
	long long a[3][3];
}I=(Matrix){1,0,0,0,1,0,0,0,1};
Matrix operator *(Matrix A,Matrix B){
	Matrix C;
	for (int i=0;i<3;i++)
		for (int j=0;j<3;j++){
			C.a[i][j]=0;
			for (int k=0;k<3;k++)
				C.a[i][j]+=A.a[i][k]*B.a[k][j];
			C.a[i][j]%=mo;
		}
	return C;
}
Matrix operator ^(Matrix A,int B){
	Matrix C=I;
	for (;B;B>>=1,A=A*A)
		if (B&1) C=C*A;
	return C;
}
int main(){
	Matrix P=(Matrix){1,2,1,0,1,1,1,2,2},Q={1,2,1,0,1,1,0,0,1};
	Matrix ans=(Matrix){1,0,0,0,0,0,0,0,0};
	int n,m;
	scanf("%d%d",&n,&m);x[0]=-1;
	for (int i=1;i<=m;i++){
		scanf("%d",&x[i]);
		ans=ans*(P^(x[i]-x[i-1]-1))*Q;
	}
	ans=ans*(P^(n-x[m]-1));
	printf("%lld\n",ans.a[0][2]);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:28:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);x[0]=-1;
                     ^
./Main.cpp:30:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&x[i]);
                    ^

Judge Result